ZrO2 Content Research Articles

Contribution to the Understanding of the Dielectric Breakdown Mechanism of ZTA Ceramics

Herein, the breakdown mechanism of alumina‐based ceramics (Al2O3–ZrO2) is studied. The specimens are characterized for their density, phase structure, micromorphology, breakdown process, and breakdown channel by micro computed tomography, high‐speed cameras, etc. The study reveals that the dielectric breakdown stability of the samples shows a decreasing trend and the dielectric loss shows an upward trend with the increase of ZrO2 content. The tetragonal phase zirconia is beneficial to enhance the dielectric breakdown strength of the sample, which is related to the martensitic transformation to prevent crack propagation. Before the ceramic breakdown, the insulating oil first breaks down, causing electric sparks. Once the ceramic breakdown occurs, the charges are rearranged, and a large amount of heat energy is generated instantly to melt the substance around the breakdown channel and erupt to the surface to form pits under the action of high internal stress.

Compositional optimization of high-solid-loading ceramic cores via 3D printing

In this study, the effects of ZrO 2 mineralizer on the curing behavior of a silica-based core slurry and the microstructure and properties of the core were analyzed to optimize the properties of the samples. The results show that ZrO 2 addition aggravates the light scattering effect during the curing process, which increases the mis-cured region. However, ZrO 2 readily reacts with the fused silica glass in the matrix to form ZrSiO 4 , which inhibits the initiation and propagation of cracks and improves the high-temperature mechanical properties of the 60 vol% high-solid-loading core slurry. The content of ZrO 2 mineralizer in the slurry should be controlled within the range of 2.0–2.5 vol% for optimal mechanical performance.

Thermophysical Properties in the YNbO4─ZrO2Pseudo‐Binary Phase Diagram with YNbO4‐Rich End

The matrix YNbO4ceramics with a series of content of ZrO2is synthesized by the conventional solid‐state reaction method in the present article. Owing to the similarity in structure, the YNbO4parent lattice is capable of solubilizing a large number of Zr atoms until its content exceeds 30 mol%. Lattice distortion introduced by the dopant leads to the shift of X‐Ray diffraction (XRD) and the increase of full width at half maximum (FWHM) in the Raman‐active peak. The results of the scanning electron microscope and energy‐dispersive spectroscopy reveal that the ZrO2that exists in the YNbO4matrix as a second phase can significantly enhance polycrystalline sintering resistance, presenting minimum grain size under the same sintering condition. The results of thermophysical properties indicate that the investigated compositions in the YNbO4─ZrO2pseudo‐binary phase show lower thermal diffusivity and thermal conductivity than that of both pure phases. The minimum thermal conductivity is 1.5 W m−1 K−1, which is lower than that of 8YSZ. Furthermore, its heat transfer obeys phonon to phonon and phonon to defect scattering mechanisms.

A Novel Epoxy Resin-Based Composite with Zirconium and Boron Oxides: An Investigation of Photon Attenuation

We have attempted to develop the gamma radiation shielding abilities of newly prepared epoxy composites by introducing ZrO2. The radiation shielding parameters are experimentally reported below. The experimental setup included an HPGe detector and different radioactive point sources which emitted photons with energies of 0.06, 0.662, 1.173, and 1.333 MeV. The gamma radiation shielding abilities of the epoxy composites were examined in the context of the linear attenuation coefficient (LAC), half-value layer (HVL), radiation absorption ratio, and other factors. The experimental and Phy-X results for the LAC were compared, and acceptable consistency was reported. The lowest LAC values were reported for EBZr-0 (free of ZrO2), and we found that the photon attenuation competence of the present epoxy improved as a result of increasing the ZrO2 content. We compared the LAC values for the present epoxy composites with other samples, and we found that the prepared composites with 20% to 40% ZrO2 had higher LAC values than epoxy with 30% Yahyali Stone. The HVL lengths of the epoxy composites reduced with the addition of ZrO2 for the four selected energies, which confirmed that introducing ZrO2 improves the radiation absorption abilities of epoxy composites. At 0.06 MeV, the HVL for the ZrO2-free epoxy was 2.60 cm, which fell to 0.23 cm after adding 40% ZrO2. The mean free path (MFP) for the prepared composites was less than 1 cm at 0.06 MeV (standard for EBZr-0), while it was 1.32 cm for EBZr-10. For the other energies, it was higher than 6 cm, and became higher than 10 cm at 1.333 MeV for all composites. The obtained results suggest that non-toxic, natural, and cheap epoxy composites with high ZrO2 content have the potential to improve the gamma ray shielding competence of epoxy composites for low energy radiation applications.

Comprehensive analysis of the microstructure, properties and environmental performance of Al2O3-ZrO2 composites obtained via centrifugal slip casting

This research investigates the possibility of preparing Al2O3-ZrO2 composites with different proportions of the Al2O3 and ZrO2 phases by centrifugal slip casting (CSC) method and the effect of the solid phase content (50 vol%, 45 vol%, 40 vol%) on the microstructure and selected properties of the produced materials. The hardness results showed that all the series produced were characterised by high hardness, in the range of 16–19 GPa. The results of the static compression test demonstrated that increasing the solid phase content of the slip in the samples promotes the formation of fewer cracks during the monotonic compression loading of the composites. The LCA results demonstrated that as the content of ZrO2 in the composites increase, their environmental footprint increases.

Corrosion behavior of TiZrHfBeCu(Ni) high-entropy bulk metallic glasses in 3.5 wt. % NaCl

The corrosion behavior of TiZrHfBeCu(Ni) high-entropy bulk metallic glasses (HE-BMGs) has been investigated. The TiZrHfBeCu(Ni) HE-BMGs exhibited high corrosion resistance in 3.5 wt. % NaCl solution because of accumulation of ZrO2 and TiO2 in the passive film. Ni promoted increases of the ZrO2, TiO2, and HfO2 contents and a decrease of the BeO content, which improved the HE-BMG corrosion behavior. Compared with Zr41.2Ti13.8Ni10Cu12.5Be22.5 BMG, the high-entropy effect of HE-BMGs can significantly reduce the atomic mobility, which inhibits outward migration of Cu, reduces the kinetics of the dissolution reaction, and inhibits inward erosion by Cl−, thereby improving the corrosion performance.

The translational, rotational, and phonon dynamics of water in ZrO2 /water nanofluid

The translational, rotational, and phonon dynamics of water in zirconium oxide (ZrO2) nanofluid were investigated by quasi-elastic neutron scattering, 17O NMR relaxation, and inelastic X-ray scattering, respectively. The particle size of ZrO2 is 3～100 nm, and the concentration of ZrO2 nanoparticles is 5, 10, 20, and 30 wt%. The translational and rotational motions of water molecules become retarded with increasing the concentration of ZrO2. This indicates that there is an attractive interaction between water molecules and the surface of the nanoparticles. The high-frequency sound velocity of the nanofluid obtained from phonon dynamics measurements is slightly larger than that of pure water although it is not much difference compared to the case of the translation and rotation. These findings indicate that water dynamics in the nanofluid is different from that of the bulk. It might be reasons for the enhancement of the thermal conductivity of the nanofluid.

Advanced zirconia ceramics stabilized with yttria and magnesia: Structure and Vickers microhardness

The samples 8YSZ containing 70, 75, 80 mol% ZrO2 and other oxides were prepared by.a high temperature solid state reaction process. Using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and spectroscopic methods were evaluated the effect of oxide addition on the properties of yttria-doped zirconia.X-ray data shows the formation of zirconia (Y-doped), YSZ and/or tetragonal zirconia crystalline phases in all samples. IR data indicate the stretching vibrations of the Si–O bonds from tetrahedral [SiO4] units and the stretching vibrations of the Fe–O bonds from [FeO6] structural units, respectively. EPR results indicate the destroying of the local ordering of the Fe+3 ion vicinities situated in the rhombic distorted octahedral geometries by the increasing of ZrO2 content in the host ceramic.The highest values of Vickers hardness were recorded for the ceramics containing 70 and 75 mol% ZrO2. This superior performance can be explained considering the presence of a smaller amount of monoclinic ZrO2 crystalline phase in the ceramic structure.The analysis of the X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) data shows the presence of Fe+2 and Fe+3 ions. In the ceramics with higher ZrO2 contents the iron atoms adopt a randomly structure due to the highly distorted [FeO6] structural units and non-equivalent Fe–O distances in the first coordination shell.

Hybrid coating of polydimethylsiloxane with nano-ZrO2 on magnesium alloy for superior corrosion resistance

To enhance the corrosion resistance of magnesium alloys, an organic-inorganic coating of polydimethylsiloxane (PDMS) hybridized with ZrO2 nanoparticles is developed, where the PDMS is selected as the polymeric matrix for superhydrophobic surface, and nano-ZrO2 particles as a physical barrier to strengthen and densify the polymeric matrix. The nanocomposite materials were characterized by field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectrophotometry (FT-IR), and X-ray diffraction (XRD). Electrochemical, dropping corrosion, and salt spray tests were carried out to evaluate the effect of the amount of ZrO2 on the corrosion property of the PDMS-ZrO2 coatings. Thermal stability, hydrophobicity, and corrosion resistance of the composite coatings are substantially improved by the introducing ZrO2 modifier into PDMS matrix. Depending on the ZrO2 content, the PDMS-ZrO2 hybrids exhibit superior corrosion resistance, where the corrosion current density of PDMS-ZrO2 coatings containing 10% (wt.%) ZrO2 decreases about five orders of magnitude compared with Mg alloy substrate. Furthermore, it is noteworthy that ZrO2 nanoparticles are filled in the PDMS matrix to provide a long-term protection in the salt spray test up to 210 h. The PDMS-ZrO2 coatings demonstrate an excellent shielding ability for the Mg alloy, which is attributed to the strong hydrophobic surface of PDMS and compact network structure separated by the physical barrier of ZrO2 nanoparticles in the PDMS chains. The proposed mixed matrix membrane guides a design direction for highly water-repellent coating with a long-term corrosion protection performance.

Effect of ZrO2 on sintering behavior and properties of h-BN/ZrO2 composites by spark plasma sintering

The h-BN/ZrO2 composites with different 3Y–ZrO2 content were prepared by spark plasma sintering at 1800 °C. The sintering behavior, bulk density, apparent porosity, thermal conductivity, thermal expansion coefficient, bending strength, thermal shock resistance, microstructure and phase were analyzed. The optimum specimens were used to test the resistance to corrosion of molten steel for 10, 20, 40, 80 min respectively. The results indicated that ZrO2 could facilitate the sintering process of h-BN matrix under the action of spark plasma. Especially, for the composites with 30 wt% 3Y–ZrO2, the porosity could decrease to 1.1% and the flexural strength could exceed 150 MPa. The microstructure showed the h-BN grains and 3Y–ZrO2 grains are closely combined. The XRD patterns indicated that the t-ZrO2 diffraction peak gradually enhanced with the increase of density. With the increase of erosion time, the erosion rate increased significantly. After the surface of the specimen is eroded, the erosion resistance of the matrix would decrease significantly. This h-BN/ZrO2 could be as side-dam used in the thin strip continuous casting process.

Combined effect of low ZrO2 content and carbon nanostructures on mechanical and wear properties of hot-pressed Al2O3/ZrO2 hybrid nanocomposites

Al2O3/ZrO2 systems with higher ZrO2 amounts (≥20 wt%) are known to offer improved properties such as fracture toughness, but are restricted in their hardness, wear and strength performances. The incorporation of a third phase carbon nanostructure (such as CNTs and GN) to Al2O3/ZrO2 reinforced with low ZrO2 content (≤5wt%) has emerged as a novel process to overcome this property trade-off by exploring the remarkable mechanical properties of these hybrid nanocomposite systems. Therefore, in the current work, colloidal mixing followed by hot-pressing process (@ 1600°C) were used to consolidate monolith Al2O3, Al2O3/ZrO2, Al2O3/ZrO2/CNTs and Al2O3/ZrO2/GN nanocomposite structures using low ZrO2 content (4wt%) and optimum amounts of CNTs (2wt%) and GN (0.5wt%) as the hybrid reinforcement phases. Microhardness, fracture toughness and flexural strength properties were improved from 19GPa, ∼3MPa.m1/2 and ~260MPa up to 24GPa, ∼7MPa.m1/2 and ~374MPa respectively, with hybrid additions of ZrO2/CNTs and ZrO2/GN to the monolith Al2O3. The primary source of the property enhancement in the hybrid nanocomposites was due to reduction in the matrix and ZrO2 grain sizes (decreased up to ∼78%), good interaction between reinforcement phases and combined mechanisms such as crack bridging and deflection, matrix grain wrapping and grain gluing by CNTs and GN. The wear rate of the parent Al2O3 was also improved from 9.71 × 10−5 mm3/N.m up to 0.81 × 10−5 mm3/N.m (showing ∼92% decrease) with ZrO2/CNTs and ZrO2/GN hybrid inclusions, which was attributed to the overall enhanced mechanical properties and wear resistant mechanisms during the dry sliding.

Channeled PM10, PM2.5 and PM1 Emission Factors Associated with the Ceramic Process and Abatement Technologies.

A sampling methodology and a mathematical data treatment were developed that enable to determine not only total suspended particulates (TSP) emitted at channeled sources but also the PM10, PM2.5, and PM1 mass fractions (w10, w2.5, and w1) and emission factors (E.F.), using a seven-stage cascade impactor. Moreover, a chemical analysis was performed to identify the elements present in these emissions. The proposed methodology was applied to different stages of the ceramic process, including ambient temperature (milling, shaping, glazing) and medium–high-temperature (spray-drying, drying, firing, and frit melting) stages. In total, more than 100 measurements were performed (pilot scale and industrial scale), which leads to a measurement time of 1500 h. Related to the mass fractions, in general, the mean values of w10 after the fabric filters operated at high performance are high and with little dispersion (75–85%), and it is also observed that they are practically independent of the stage considered, i.e., they are not significantly dependent on the initial PSD of the stream to be treated. In the case of the fine fraction w2.5, the behavior is more complex (w2.5: 30–60%), probably because the only variable is not the cleaning system, but also the nature of the processed material. Regarding abatement measures, the use of high-efficiency cleaning systems considerably reduces the emission factors obtained for fractions PM10, PM2.5, and PM1. In reference to chemical analysis, the presence of ZrO2 and Ni in the spray-drying and pressing stages, the significant concentration of ZrO2 in the glazing stage, the presence of Pb, As, and Zn in the firing stage, and the presence of Zn, Pb, Cd, and As compounds in the frits manufacturing should all be highlighted. Nevertheless, it should be pointed out that the use of some compounds, such as cadmium and lead, has been very limited in the last years and, therefore, presumably, the presence of these elements in the emissions should have been also reduced in the same way.

Spark plasma sintering of ZrO2 reinforced Ni-Cr alloy: Microstructure and mechanical behavior

Ni-Cr-ZrO2 composites with varying amounts of ZrO2 additive (5 wt%, 7.5 wt%, 10 wt% and 12.5 wt%) were fabricated using spark plasma sintering method at a sintering temperature of 1000°C, heating rate of 100°C/min, holding time of 5 min, and a pressure of 50 MPa. The effect of ZrO2 addition on the microstructure, tribological and mechanical properties of the developed composites were studied. The results showed that maximum densification was attained at 10 wt% ZrO2. Further increase in the fractions of ZrO2 within the composites results in a decrease in the relative density of the sintered composite. A significant increase in hardness from 433.24 HV to 510.11 HV and elastic modulus from 252.67 GPa to 294.6 GPa was observed in the fabricated samples as the ZrO2 content increase from 5 to 12.5 wt%. An appreciable improvement in the wear performance of the sintered samples was obtained with increasing ZrO2 content. The observed improvement in the properties of the sintered composites was attributed to the presence of the hard dispersoids of ZrO2 and formation of solid solution strengthening and hard Cr3Ni2 phases within the matrix of the sintered composites.

In-situ fabrication of 3D/1D p-NiO/p-ZrO2 heterojunction composites with enhanced photo-degradation activity towards methyl orange and benzimidazole

In current work, p-p type NiO/ZrO2 composites (NZO-1 and NZO-2) were fabricated with the help of single step co-precipitation route. NiO to ZrO2 ratio was kept 9:1 and 8:2 for NZO-1 and NZO-2, respectively. As prepared composites were characterized by different physiochemical techniques. XRD data confirmed that cubic and monoclinic crystal phases of NiO and ZrO2 were present in both NZO-1 and NZO-2 composites. With the increase in concentration of ZrO2, crystallite size of NiO/ZrO2 was decreased from 16 nm to 14 nm. SEM analysis showed the formation of 3D quasi spherical particles of NiO and 1D nanoneedles of ZrO2. With FT-IR investigations different M − O bonds related to Ni–O and Zr–O were observed in NZO-1 and NZO-2. When used for photocatalytic activities, NZO-2 outperformed as compared to NZO-1 and pure constituents (NiO and ZrO2). In brief, NZO-2, NZO-1, NiO and ZrO2 removed 93, 80, 62 and 45% of Methyl orange (MO) dye in presence of natural sunlight within 120 min. Clearly, NZO-2 hold optimum concentrations of NiO and ZrO2 with a kinetic rate constant value of 0.019 min−1. Scavenging experiments disclosed electrons, superoxide radicals and holes were the main species involved in the photo-removal of MO. For benzimidazole, sufficient photo-degradation activity (57%) was observed in presence of NZO-2. Photo-catalytic investigations suggested that NZO-2 can be used as efficient photocatalyst for the treatment of multiple pollutants from contaminated water.

Solid particle erosion studies of ceramic oxides reinforced water-based PU nanocomposite coatings for wind turbine blade protection

Wind energy has been regarded to be one of the renewable energies to rely on for the future. In tropical countries like India maintenance of wind turbine blades is a challenging task. Solid particle erosion is one of the root causes of wind turbine blade damage resulting in reduction in energy production. In the present study, in-house synthesized ceramic oxide nanoparticles such as Al2O3, ZrO2, and CeO2 are used as fillers for reinforcement of water-based polyurethane (PU) coatings on glass fibre reinforced polymer (GFRP) substrates for solid particle erosion resistance for the first time. Al2O3, ZrO2, and CeO2 nanoparticles have been prepared by solution combustion synthesis method using urea, glycine, and oxalyl dihydrazide, respectively, as fuels. These ceramic nanoparticles are found to crystallize in corundum, tetragonal, and cubic structures, respectively, as confirmed by X-ray diffraction studies. Field emission scanning electron microscopy shows the porous microstructure of the oxide products due to the release of gases in course of preparation. Transmission electron microscopy studies of these nanoparticles show corresponding lattice fringes in their high-resolution images. Observed Al–O, Zr–O, and Ce–O vibrational modes in Raman spectra confirm the formation of corresponding oxides. The oxidation states of Al, Zr, and Ce in the respective oxides are found to be +3, +4, and +4, respectively, as demonstrated by X-ray photoelectron spectroscopy. The nanocomposite coatings consisting of PU and Al2O3, ZrO2, and CeO2 nanoparticles have been developed by a simple spray method on GFRP substrates. The solid particle erosion resistance tests of coatings have been studied at varied concentrations of Al2O3, ZrO2, and CeO2 nanoparticles at impinging angles of 30° and 90°. It has been observed that ZrO2, and CeO2 nanoparticles-reinforced PU coatings show better solid particle erosion resistance compared to Al2O3-reinforced coating. Among different concentrations studied here, coatings with 15 wt% filler concentrations offer a relatively low erosion rate than the other concentrations at both impinging angles. However, GFRP substrate and PU coating are observed to show much higher erosion rate compared to nanoparticles reinforced PU coatings.

Synthesis of hollow ceria-zirconia solid solution particles by spray pyrolysis with organic ligands and its oxygen storage capacity

CeO2-based materials have been explored as oxidative catalysts owing to the reversible oxygen absorption and release behavior. The catalytic property is stabilized by addition of ZrO2 to form the solid solution. Hollow CeO2-ZrO2 solid solution particles were prepared by a spray pyrolysis method with organic additives, characterized by SEM, XRD and TEM, and evaluated for oxygen storage capacity (OSC). Spherical hollow particles with a size of about 500 nm formed, which were composed of about 10 nm nanoparticles. CeO2-rich particles had cubic crystal structure, while tetragonal phase was included in ZrO2-rich particles. The addition of organic ligands was effective to form uniform solid solution and increase specific surface area. The spray-pyrolysis temperature should be low to keep the specific surface area. At 50 mol% ZrO2, although the specific surface area was not so high as 20 m2/g, the maximum OSC of 650 μmol-O2/g was achieved. It was found that the OSC depends on ZrO2 content and the oxygen release rate increases with specific surface area.

The microstructure tailoring and property improving of directed energy deposited Al-Zn-Mg-Cu alloy modified with various Si and ZrO2 contents

Al-Zn-Mg-Cu alloys are traditional lightweight materials with extraordinary mechanical properties. Nevertheless, the manufacturing of Al-Zn-Mg-Cu alloys by directed energy deposition (DED) technique is still a tough problem since these alloys are prone to hot-cracking during the rapid solidification process of DED. In this paper, the co-incorporation of Si and ZrO 2 into the Al-Zn-Mg-Cu alloy was adopted for alleviating solidification shrinkage and enhancing mechanical properties. After the addition of Si, cracks are completely eliminated and the microstructure is refined due to the formation of Si rich eutectic phases. The average grain size is further decreased when ZrO 2 was added and the elevation of ZrO 2 amount facilitates the declination. The combined effects of Si and ZrO 2 induce the enhanced tensile properties (241 MPa in tensile strength, 160 MPa in yield strength and 4.1% in elongation) of the Al-Zn-Mg-Cu alloy modified with 2.9 wt% Si and 1.5 wt% ZrO 2 , which are further improved after T6 treatment (304 MPa in tensile strength, 225 MPa in yield strength and 4.3% in elongation). This paper indicates that the present approach can enable the manufacturing of crack free hard-to-weld Al-Zn-Mg-Cu alloys with ultrafine grains by DED through adding appropriate ceramic inoculants. • Si and ZrO 2 were added for crack elimination and mechanical property enhancement. • Columnar grains are transformed into equiaxed grains after adding ZrO 2 . • The tensile strength is increased to 304 MPa after T6 treatment.

Influence of zirconia on the sintering behaviour and mechanical properties of reaction-sintered mullite-based composite ceramics

ABSTRACTHigh-performance mullite-based composite ceramics were prepared successfully using natural kaolin and alumina as raw materials and ZrO2 as an additive. The influence of sintering temperature and ZrO2 content on the sintering behaviour and mechanical properties of zirconia-toughened mullite ceramics was studied systematically. With increasing sintering temperature from 1450°C to 1560°C, the primary phases of as-sintered composite ceramics were mullite and corundum with a small amount of ZrO2, and the bulk density of the composite ceramics increased from 2.29 to 2.72 g cm–3. Furthermore, the ZrO2 phase transition promoted transgranular fracture, and ZrO2 grains were pinned at the grain boundaries, thereby enhancing the mechanical strength of the composite ceramics. Moreover, the AZS12 sample, with 12 wt.% ZrO2 and sintered at 1560°C, had the greatest flexural strength and fracture toughness of 91.6 MPa and 2.47 MPa m–1/2, respectively. Adding ZrO2 to the composite ceramics increased their flexural strength by ~37.6%.

Vacuum sintering of Yb2O3 transparent ceramics: Effect of ZrO2 concentration on structural and optical properties

• Highly transparent ytterbium oxide (Yb 2 O 3 ) ceramics were successfully prepared by vacuum sintering method using ZrO 2 as a sintering aid. • ZrO 2 was found to be an effective sintering additive that can effectively inhibit Yb 2 O 3 grain growth and promote the removal of residual pores. • The effects of ZrO 2 doping concentration on the crystal structure, microstructure, optical transmittance, and band gap of Yb 2 O 3 transparent ceramics were studied for the first time. In this study, highly transparent Yb 2 O 3 ceramics were successfully fabricated via vacuum sintering at 1800 °C for 10 h with ZrO 2 as a sintering additive. The effect of zirconia doping concentration on crystal structure, microstructure, and optical properties of Yb 2 O 3 transparent ceramics was investigated. It was found that the introduction of zirconia could effectively prohibit grain growth while promoting the removal of residual pores. The mean grain size decreased from 39.04 µm to 4.27 µm as the Zr 4+ content increased from 0 to 5 at%. The 3 at% ZrO 2 -doped Yb 2 O 3 transparent ceramics have the best optical quality, with a transmittance of 75% at 1100 nm and about 81% in the mid-infrared region. This study indicates that Yb 2 O 3 transparent ceramics with good optical properties can be obtained by properly adjusting the addition amount of ZrO 2 . On this basis, the absorption spectra, emission spectra, and fluorescence lifetime of Yb 2 O 3 transparent ceramic were investigated. High transmittance and high activation cation density make Yb 2 O 3 transparent ceramics potential candidates for thin-disk laser elements.

Improving the tensile, toughness, and flexural properties of epoxy resin based nanocomposites filled with ZrO2 and Y2O3 nanoparticles

The current work is directed to improve the tensile, toughness, and bending properties of epoxy resin (EPR) based nanocomposites (NCs) by using zirconium dioxide (ZrO2) and yttrium oxide (Y2O3) nanoparticles (NPs). The EPR was mixed with differing concentrations of ZrO2 and Y2O3 NPs, and triethylenetetramine was applied as crosslinking agents. The formation of NCs and the NPs dispersion inside the EPR matrix was confirmed by X-ray diffraction (XRD) analysis. The effect of NPs concentration on the mechanical behavior of host EPR was illustrated by conducting tensile and bending tests. The mechanical properties such as tensile strength, breaking elongation, Young’s modulus, and toughness were studied through the tensile test; in addition, a three-point bending flexural test was employed to investigate the flexural strength, flexural strain at break, and flexural modulus of the fabricated NCs. The results showed that the EPR NC samples at low NPs content exhibit considerably high mechanical performance compared to pure EPR. It was found the EPR NC sample with 1 wt% of ZrO2 NPs shows the highest Young’s and bending modulus, as well as the toughness. However, the highest performance of EPR doped Y2O3 NPs was achieved by adding 1.5 wt% of dopant. The improvement in toughness by 23.4 % for ZrO2 and 19.6 % for Y2O3, was attributable to the large increase in tensile strength as a result of good interaction between the EPR and NPs, as the elongation at break was not significantly affected by adding NPs.